Weight-saving... Best value for money?

[Groundoggy]

Tires and a lightweight wheelset gives the most noticeable return - not even a debate about it.

It isn't just the weight savings - it is the rotating weight savings that is the key. That will provide you with the most noticeable difference in your bike. A set of lightweight Kevlar/Aramid tires provides a noticeable improvement in acceleration IMO. Put them on a lightweight wheelset with double butted spokes and alloy nipples and you feel like a sprint champ. You can buy a nice set of used wheels for $100-$200 depending on how much non-Chris King bling you want for hubs.

Beyond that I would say a lightweight seatpost and bar will provide the best improvement in comfort. The extra little forgiving bend in lightweight bars and posts is a nice comfort feature for constant riders (don't go too light if you are or ride heavy). A lightweight saddle also figures here.

The next upgrade I would suggest is a Ti bottom bracket - but only if you are or ride lightish (too many horror stories read of broken Ti BB axles causing massive, spurting bleeding of the ankle - although I have never seen this myself). That's a big hunk of metal being replaced by Ti.

Beyond that - your choice.

 

[doctor-bond]

And for many, here, the only spring, um, ness (of any note) is in the tyres. The real flaw in the debate is the presumption that either approach is mutually exclusive. Surely if you're willing to go to the effort and expense of lightweight kit, it's worth a bit of effort in lightening yourself.

The rider is the spring: most of his or her weight is 'sprung' (starting above the ankle, but mostly, above the knee) and so the body weight is a different kind of weight to eg the frame or stem. True, if the rider in question has a better power to weight ratio, then they become a more effective spring. So, pre-ride bowel and bladder evacuation is indeed a cost effective route to efficiency.

But I'd bet a titanium quill bolt that even those with a poor power to weight ratio (ie lardy unfit types) will feel a much greater benefit by riding a lighter bike (especially lighter wheels) than loosing the equivalent poundage from around the waist - or wherever else it has gathered .... Sadly I lack the engineering credentials to create a suitable experiment to back up my claims.

 

[Groundoggy]

.... Sadly I lack the engineering credentials to create a suitable experiment to back up my claims.

When engineering skills fail, just Google and fake it.

Upgrade your wheels, otherwise lose weight.

http://van.physics.illinois.edu/qa/listing.php?id=7559

Q:
I have a two-part question concerning rotational vs. static weight on a bicycle; sorry if some or all of this is already on your site, but I didn't find it. I've heard (and experienced) that changing your wheels for lighter ones makes more of a difference on a bike than lightening parts on the frame, since wheels are rotational weight. So I'm wondering 1)if there is a ratio of rotational to static weight change as a rule of thumb; 2)and is all static weight equal--in other words if I buy a two-pound lighter frame, is it the same as just losing two pounds myself? Thanks in advance, and I hope this gives you physics guys something to think about. Oh, I don't speak "science" so something in translation will be appreciated!
- mark bloom (age 50)
chico, ca usa
A:
Nice questions.
Yes, the wheel weight counts more than the frame weight. The reaon is that when you accelerate the bike everything moves forward together but the wheels also rotate. The average velocity over the whole wheel is the same as the rest of the bike, because the different parts move all the different directions in a circle. however, energy goes as the square of the velocity, and the rotational energy of the wheel just adds to the energy of the average motion. So you have to pump more energy into the bike to get a pound of wheel moving than to get a pound of frame moving. If all the weight of the wheel were out at the rim (which isn't too far from true) the total wheel energy per pound would be twice the frame energy per pound, i.e. equal rotational and static weight. The real rotational number would be a little less.
Of course if you're going uphill, the extra work to lift the bike against gravity only depends on the ordinary weight, not how it's distributed.
As for weight on you or the bike, I guess they count the same, except that the weight on you has to get lugged around even when you're not on the bike.

Mike W.

 

[FluffyChicken]

You cannot work out the most cost effective weight gain is until you know what you have.

You might have light tyres and don't realise.
Tyres are a good choice but still get a tread width that is comfortable and grips for you. Don't go silly just for the sake of it. 330g tyres are crap in all but the best of the canal paths or dry forest
It's good to buy and consider if you're looking at some already.

150g inner tubes are only a few quid more than 200g+ Tesco/Schwalbe specials, drop to less and I find they either do not fit the wide tyres or puncture with he thinnest thorn and do not seal around hawthorns so the air comes out quicker.

Wheels, if you can pick them up cheap, in good condition can make the bike better. (better bearings, braking surface etc.)
BUT you need to know what you have and what you are buying.


If you're heavy, don't go too light. Ti bottom bracket (e.g. RaceFace Taperlights) often have a max recommended weight.
Other parts will be similar.

No point buying new Alu bars if you have them already. Have steel ones then tenner could get you a lighter bar.

Seat, but then comfort (or look) often counts there.

Steel setpost, steel stem of the heavier type.
Pick up a cheap Alu version.

etc.

But know what you have first and most of all look out for bargains or sales.

 

[FluffyChicken]

Oh and weight saving isn't all about riding, it's about lifting the damn thing over styles!

 

[Rampage]

You cannot work out the most cost effective weight gain is until you know what you have.

That's very true.
I wanted to buy lighter wheels for my Klein for around two years. When I finally had some spare money I found out the weight of the wheels I wanted and it turned out my wheels were already really light!
I think I'd have made the bike heavier if I hadn't weighed my old wheels first!

 

[Agency_Scum]

A while back on this site and my local one I started threads titled " Losing Weight the REASONABLE Way. " Being poor, 6'6" and 18 stone I'm not going to blow my savings on some CNCed frippery that'll implode as soon as mud appears. The big ones are...1. Go rigid 2. Use Vs instead of discs 3. Take time to do it 4. Gripshifters 5. Ditch the crap ( over loaded back packs, chain tensioners, bar ends, brake stiffeners etc.